QR code FAQ
Common questions answered in one place.
Answers
- Do QR codes expire?
- Static QR codes (what SwiftQRCode generates) never expire. The data is encoded in the code itself.
- Can I edit a QR code after printing?
- No — static codes are immutable. If you need editable destinations, put a short URL you control into the code and change the redirect later.
- How big should a QR code be?
- Rule of thumb: the QR's width should be ~1/10 of the expected scanning distance (so 3 cm for a 30 cm scan).
- Do inverted (light on dark) QR codes work?
- Most modern scanners handle them, but the QR spec prefers dark modules on a light background. Stick to that for safety.
- Can QR codes carry viruses?
- Not by themselves — they only encode text. But a QR pointing to a malicious URL is a risk. Always preview scans before opening.
- What's the maximum data?
- Up to ~4,296 alphanumeric characters, but smaller payloads produce simpler, more scannable codes.
- Why use SVG?
- SVG is vector and scales without losing quality — perfect for print and high-DPI screens.
- Is my data sent anywhere?
- No. SwiftQRCode runs entirely in your browser.